#include<iostream>
#include<string>

using namespace std;

int main(){

	string s1;
	s1="Hello woooorld";
	string subStr=s1.substr(7,4);
	cout<<subStr<<endl;

	string s2="英雄哪里出来&&夜深人静写代码";
	int pos=s2.find("&&");
	string s3=s2.substr(0,pos);
	string s4=s2.substr(pos+2);
	cout<<s3<<' '<<s4<<endl;


	return 0;
}
